A concentration of a biogenic substance such as glucose contained in a living body is measured on the basis of reflected light or transmitted light irradiated on the living body.
Patent Document 1 discloses a method for measuring a three-dimensional distribution of a biogenic substance in a living body. According to the method, first, laser lights of various wavelengths are irradiated so that they are focused in the living body. The reflected light is analyzed by spectroscopy while the region where the laser lights are irradiated and the position where the laser lights are focused are scanned by the irradiated lights to measure the three-dimensional distribution.
Patent Document 2 discloses a method for measuring a glucose concentration. According to the method, first, a particle is implanted in the upper layer of a skin. The particle contains a reagent to change a fluorescence property on the reaction with glucose. Next, light of an exciting wavelength is irradiated from the outside of the living body to measure fluorescence generated at the particle through the skin. On the basis of the measured fluorescence, the glucose concentration is measured.